Program telecast monitoring using watermarks

Abstract

Methods, apparatus and articles of manufacture for program telecast monitoring using watermarks are disclosed. Example methods disclosed herein to watermark media can include encoding the media with a sequence of watermarks, a watermark in the sequence of watermarks including payload data identifying the media. Such example methods can also include, modifying the sequence of watermarks to further include a data pattern associated with a particular transmission of the media. In some examples, respective watermarks in the sequence of watermarks are to be modified to include respective portions of the data pattern, wherein the respective portions, when combined, form the data pattern.

What is claimed is: 
     
       1. A method to watermark media, the method comprising:
 encoding, with a processor, the media with a sequence of watermarks, a watermark in the sequence of watermarks including payload data identifying the media; and 
 after the sequence of watermarks has been encoded in the media, modifying, with the processor, the sequence of watermarks encoded in the media to further include a data pattern associated with a particular transmission of the media, respective watermarks in the sequence of watermarks to be modified to include respective portions of the data pattern, wherein the respective portions, when combined, form the data pattern. 
 
     
     
       2. A method as defined in  claim 1 , wherein the data pattern includes a sequence of bits, and the respective portions of the data pattern include respective subsets of the sequence of bits. 
     
     
       3. A method as defined in  claim 1 , wherein the payload data includes a source identifier and a number within a range of numbers uniquely associated with the media and the source identifier. 
     
     
       4. A method as defined in  claim 1 , wherein modifying the sequence of watermarks includes, after the sequence of watermarks has been encoded in the media, replacing respective portions of respective ones of the watermarks in the sequence of watermarks with different respective portions of the data pattern. 
     
     
       5. A method as defined in  claim 1 , wherein modifying the sequence of watermarks includes, after the sequence of watermarks has been encoded in the media, adding different respective portions of the data pattern to respective ones of the watermarks in the sequence of watermarks. 
     
     
       6. A tangible machine readable medium comprising machine readable instructions which, when executed, cause a machine to at least:
 encode media with a sequence of watermarks, a watermark in the sequence of watermarks including payload data identifying the media; and 
 after the sequence of watermarks has been encoded in the media, modify the sequence of watermarks encoded in the media to further include a data pattern associated with a particular transmission of the media, respective watermarks in the sequence of watermarks to be modified to include respective portions of the data pattern, wherein the respective portions, when combined, form the data pattern. 
 
     
     
       7. A tangible machine readable medium as defined in  claim 6 , wherein the data pattern includes a sequence of bits, and the respective portions of the data pattern include respective subsets of the sequence of bits. 
     
     
       8. A tangible machine readable medium as defined in  claim 6 , wherein the payload data includes a source identifier and a number within a range of numbers uniquely associated with the media and the source identifier. 
     
     
       9. A tangible machine readable medium as defined in  claim 6 , wherein the machine readable instructions, when executed, further cause the machine to, after the sequence of watermarks has been encoded in the media, replace a respective portions of respective ones of the watermarks in the sequence of watermarks with different respective portions of the data pattern. 
     
     
       10. A tangible machine readable medium as defined in  claim 6 , wherein the machine readable instructions, when executed, further cause the machine to, after the sequence of watermarks has been encoded in the media, add different respective portions of the data pattern to respective ones of the watermarks in the sequence of watermarks. 
     
     
       11. An apparatus to watermark media, the apparatus comprising:
 a watermark encoder to encode the media with a sequence of watermarks, a watermark in the sequence of watermarks including payload data identifying the media; and 
 a watermark modifier to modify the sequence of watermarks after the sequence of watermarks has been encoded in the media, the watermark modifier to modify the sequence of watermarks encoded in the media to further include a data pattern associated with a particular transmission of the media, respective watermarks in the sequence of watermarks to be modified to include respective portions of the data pattern, the respective portions collectively forming the data pattern. 
 
     
     
       12. An apparatus as defined in  claim 11 , wherein the data pattern includes a sequence of bits, and the respective portions of the data pattern include respective subsets of the sequence of bits. 
     
     
       13. An apparatus as defined in  claim 11 , wherein the payload data includes a source identifier and a number within a range of numbers uniquely associated with the media and the source identifier. 
     
     
       14. An apparatus as defined in  claim 11 , wherein the watermark modifier is to, after the sequence of watermarks has been encoded in the media by the watermark encoder, replace respective portions of respective ones of the watermarks in the sequence of watermarks with different respective portions of the data pattern. 
     
     
       15. An apparatus as defined in  claim 11 , wherein the watermark modifier is to, after the sequence of watermarks has been encoded in the media by the watermark encoder, add different respective portions of the data pattern to respective ones of the watermarks in the sequence of watermarks.